Method of manufacturing dry cells



' Patented Feb.17,1925. 1.52am

VICTOR YNGVE, OF SOUTH ORANGE, NEW JERSEY, AND CHARLES G. IBIRDSALL, OF

ELMI-IURST, NEW YORK, ASSIGNORS T0 MANHATTAN ELECTRICAL SUPPLY COM-PANY, INCORPORATED, OF NEW YORK, N. Y. A CORPORATION OF MASSACHUSETTS.

METHOD OF MANUFACTURING DRY CELLS.

Ito Drawing. Application filed March 28, 1924. Serial No. 702,583.

I '0 all whom it may concern:

Be it known that We, V1c'ron.Y1 cvE and CHARLES G. BIRDSALL, citizens ofthe United States, residing at South Orange, in the county of Essex andState of New Jersey, and at Elmhurst, in the county of Queens and Stateof New York, respectively, have invented certain new and usefulImprovements in Methods of Manufacturing Dry Cells, of which thefollowing is a specification.

This invention relates to an improved method of manufacturing dry cellsand more particularly to the manufacture of dry cells in which thedepolarizing mixture is in the form of compacted tablets.

'e have found that ageing the tablets will increase their structuralstrength, whereby the breakage incident to handling by means ofautomatic machinery may be materially reduced. The length of time during\rhich'the tablets are aged depends on the composition of the tablets,and upon atmospheric and temperature conditions. W'e have found thatunder normal conditions two to four hours ageing will appreciably i11-crease the strength of the tablets and that they will continue thus toimprove over a relatively long period that may amount to several weeks.WVe have found also that the ageing process can be accelerated bysubjecting the tablets to higher than room temperatures. Any increase inthe temperature speeds up the hardenim process, but temperatures of 7 5to 140 were found best.

In order to speed up the manufacturing process, the tablets as they comefrom the press are passed by any suitable means, such as an endlessbelt. through an oven heated to the desired degree and are thentransferred to the assembling machine. Instead of this method thetablets may be placed in the open in suitable containers and left therefor the desired length of time. This time depends upon the compositionof the tablets and the temperature, and in order to increase the speedof manufacture. the tablets are subjected to heat for about half anhour.

\Vhat we claim is:

l. The process of increasing the mechanical strength of depolarizingmixture for use in dry cells which consists in ageing the mixture.

2. The process of increasing the mechanical strength of tabletscompacted of depolarizing mixture which consists in ageing such tabletsfor from ten hours to one week.

3. The process of increasing the mechanical strength of tabletscompacted of depolarizing mixture, which consists in subjecting thetablets to higher than room temperatures for a certain period of timeand then assembling a dry cell out of such tablets.

In testimony whereof. we have signed our names to this specification,this 27th day of March, 1924.

VICTOR YNGVE. CHARLES G. BIRDSALL.

